Detergent compositions

ABSTRACT

A DETERGENT COMPOSITION INCORPORATED FROM 1 TO 60% BY WEIGHT OF A WATER-SOLUBLE OR WATER-DISPERSIBLE SALT OF A HETEROCYCLIC DICARBOXYLIC ACID HAVING THE GENERAL FORMULA: WHEREIN R CAN BE HYDROGEN OR A SUBSTITUENT SUCH AS BROMINE, CHLORINE, HYDROXY, CARBOXY, C1-4 ALKYL, AMINO OR ALKYL-SUBSTITUTED AMINO, THE SALT ACTS AS A DETERGENCY BUILDER, AND MAY ACT ALSO AS AN INHIBITOR FOR THE DECOMPOSITION, CAUSED BY HEAVY-METAL CATALYSIS, OF ANY PEROXYCOMPOUNDS SUCH AS PERBORATES, IN THE DETERGENT COMPOSITION.   2-(HOOC-),4-R,6-(HOOC-)PYRIDINE

ABSTRACT OF THE DISCLOSURE A detergent composition incorporates from 1 to 60% by weight of a water-soluble or water-dispersible salt of a heterocyclic dicarboxylic acid having the general formula:

HOOC coon wherein R can be hydrogen or a substituent such as bromine, chlorine, hydroxy, carboxy, C alkyl, amino or alkyl-substituted amino. The salt acts as a detergency builder, and may act also as an inhibitor for the decomposition, caused by heavy-metal catalysis, of any peroxycompounds such as perborates, in the detergent composition.

The present invention relates to detergent compositions, and in particular to fabric-washing detergent compositions, incorporting detergency builders.

At the present time there is considerable pressure being brought to bear on the manufacturers of detergent compositions to reduce the amount of phosphorus-containing compounds in such compositions. This situation has arisen because of the suggestion that the use of phosphorus-containing compounds in detergent compositions is a factor contributory to the phenomenon of eutrophication. Such phosphorus-containing compounds are generally present in detergent compositions as detergency builders. For many years the most commonly employed detergency builder has been sodium tripolyphosphate, and it is this compound in particular that is being blamed for the contribution of detergent compositions to the problems of eutrophication. It is common for detergent compositions to contain from 30 to 50% by weight of sodium tripolyphosphate. Sodium tripolyphosphate is a very efficient detergency builder and can also be manufactured cheaply.

Hence at the present time there is a need for a substitute for sodium tripolyphosphate that can be used to produce detergent compositions that clean efficiently and yet which will not interfere adversely with mans environment.

By the invention it has been found that the detergency of a detergent composition can be built efiectively using a water-soluble or water-dispersible salt of a chemical compound having the general formula:

HO C C O OH wherein R is a hydrogen atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group, an alkyl-sub stituted amino group, a carboxyl group, or an alkyl group containing from 1 to 4 carbon atoms.

Hereinafter, a water-soluble or water-dispersible salt of a chemical compound of Formula I is referred to as a heterocyclic dicarboxylic acid salt. These heterocyclic dicarboxylic acid salts are known compounds.

The invention provides a detergent composition comprising a detergent-active compound and from about 1 to about 60% by weight of a heterocyclic dicarboxylic acid salt.

Preferably, the heterocyclic dicarboxylic acid salt comprises from about 5 to about 60%, and particularly preferably from about 15 to about 55%, by Weight of the detergent composition.

Where R is an alkyl-substituted amino group, the preferred groups are N-methyl amino, N-ethyl amino, N,N- dimethyl amino and N,N-diethyl amino groups.

Where R is an alkyl group, methyl, ethyl and n-propyl groups are preferred.

It is preferred that R is a hydrogen atom, a hydroxyl group, an amino group, an alkyl-substituted amino-group,

a carboxyl group or a methyl group.

It is particularly preferred that R is a hydrogen atom or a hydroxyl group.

The heterocyclic dicarboxylic acid salt is preferably an alkali-metal salt, particularly a sodium salt, although potassium and lithium salts can be used. If desired, the heterocyclic dicarboxylic acid salt may be an ammonium or substituted ammonium salt.

It will be appreciated by those skilled in the art that the detergency building benefits of a heterocyclic dicarboxylic acid salt of the invention may still be obtained if a detergent composition incorporates the corresponding free heterocyclic dicarboxylic acid, or the heterocyclic dicarboxylic acid in a partially neutralised form, complete neutralisation of the heterocyclic dicarboxylic acid taking place when the detergent composition is dissolved in water.

The heterocyclic dicarboxylic acid of Formula I above wherein R is a hydrogen atom is pyridine-2,6-dicarboxylic acid, which is known also as dipicolinic acid.

Many conventional fabric-washing detergent compositions incorporate peroxy-compounds, such as sodium perborate, as oxygen-releasing bleaching agents. Water in which such detergent compositions are dissolved often contains minor traces of catalysts, such as heavy metal ions, which cause unwanted decomposition of the peroxycompounds to take place and hence cause a drop in the bleaching efliciency of the detergent compositions. It has been found, as an added advantage of the detergent compositions of the invention, that the heterocyclic dicarboxylic acid salts of the invention can act as inhibitors for this decomposition. The preferred peroxy-compounds are sodium perborate and sodium percarbonate, and if desired may be present in a detergent composition in an amount of from about 1 to about 30% by weight of the detergent composition.

A detergent composition of the invention will contain at least one detergent-active compound. Generally, the detergent-active content of the detergent composition will be from about 1 to about 50%, preferably from about 5 to 35%, and particularly preferably from about 10 to about 25%, by weight of the composition. The nature of the detergent-active compound or compounds in the detergent composition is not an essential feature of the invention: any of the detergent-active compounds conventionally incorporated in or proposed for use in detergent compositions may be used, and those skilled in the art of formulating detergent compositions will be familiar with these detergent-active compounds and the various amounts and combinations in which they may advanta- Patented Sept. 18, 1973 Typical anionic detergent-active compounds are watersoluble or water-dispersible salts of various organic acids. The cations of such salts are generally alkali-metals, such as sodium and, less preferably, potassium, but other cations, such as ammonium and substituted ammonium, can be used if desired. Examples of suitable organic acids are: alkyl benzene sulphonic acids, the alkyl chains of which contain from about 8 to about 20 carbon atoms, such as p-dodecyl benzene sulphonic acid and linear alkyl (C benzene sulphonic acid; the mixtures of sulphonic acids obtained by reacting linear and branched olefins, particularly linear cracked-wax or Ziegler alpha-olefins, containing from about 8 to about 22 carbon atoms, with sulphur trioxide; alkyl sulphonic acids obtained by reacting alkanes containing from about 8 to about 22 carbon atoms with sulphur dioxide/oxygen or sulphur dioxide/chlorine (followed by hydrolysis in the latter case), or by the addition of bisulphite to olefins, particularly linear cracked-wax" or Ziegler alphaolefins, containing from about 8 to about 22 carbon atoms; alkyl sulphuric acids obtained by reacting aliphatic alcohols containing from about 8 to about 22 carbon atoms with sulphur trioxide; alkyl ether sulphuric acids, obtained by reacting molar quantities of aliphatic alcohols containing from about 6 to about 18 carbon atoms with from about 1 to about 15 moles of ethylene oxide, or a suitable mixture of ethylene oxide and propylene oxide, and subsequently reacting the alkoxylated alcohol with sulphur trioxide to yield the required acid; and natural or synthetic aliphatic carboxylic acids, particularly those derived from natural sources such as tallows, coconut oil, palm oil, palm kernel oil and groundnut oil.

Examples of suitable nonionic detergent-active compounds are: condensates of alkyl-phenols having an alkyl group (derived, for example, from polymerised propylene, diisobutylene, octene, dodecene or nonene) containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with about 5 to 25 moles of ethylene oxide per mole of alkyl-phenol; condensates containing from about 40% to about 80% polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide with the reaction product of ethylenediamine and excess propylene oxide; condensates of linear or branched-chain aliphatic alcohols containing from 8 to 18 carbon atoms with ethylene oxide, e.g. a coconut alcohol-ethylene oxide condensate containing a about 6 to 30 moles of ethylene oxide per mole of coconut alcohol; long-chain tertiary amine oxides corresponding to the general formula R R R N O, wherein R is an alkyl radical containing from about 8 to 18 carbon atoms and R and R are each methyl, ethyl or hydroxy ethyl radicals, such as dimethyldodecylamine oxide, dimethyloctylamine oxide, dimethylhexadecylamine oxide and N-bis (hydroxyethyl) dodecylamine oxide; long-chain tertiary phosphine oxides corresponding to the general formula RRRP O, wherein R is an alkyl, alkenyl or monohydroxyalkyl radical containing from 10 to 18 carbon atoms and R and R" are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms, such as dimethyldodecylphosphine oxide, dimethyltetradecylphosphine oxide, ethylmethyltetradecylphosphine oxide, dimethylstearylphosphine oxide, ethylpropylcetylphosphine oxide, diethyldodecylphosphine oxide, bis- (hydroxymethyl)dodecylphosphine oxide, bis (2-hydroxyethyl)dodecylphosphine oxide, Z-hydroxypropylmethyltetradecylphosphine oxide, dimethyloleylphosphine oxide and dimethyl-Z-hydroxydodecylphosphine oxide; and dialkyl sulphoxides corresponding to the general formula RR'S 0, wherein R is an alkyl, alkenyl, betaor gammamonohydroxyalkyl radical or an alkyl or betaor gammamonohydroxyalkyl radical containing one or two other oxygen atoms in the chain, the R groups containing from 10 to 18 carbon atoms and wherein R is methyl, ethyl or alkylol radical, such as deodecyl methyl sulphoxide,

tetradecyl methyl sulphoxide, 3-hydroxytridecyl methyl sulphoxide, 2-hydroxydodecyl methyl sulphoxide, 3-hydroxy-4-dodecyloxybutyl methyl sulphoxide, 2-hydroxy- 3-decyloxypropyl methyl sulphoxide, dodecyl ethyl sulphoxide, Z-hydroxydodecyl ethyl sulphoxide and dodecyl- Z-hydroxyethyl sulphoxide.

Examples of suitable amphoteric detergent-active compounds are: derivatives of aliphatic secondary and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilising group, such as sodium 3 dodecylaminopropionate, sodium-3-dodecylaminopropanesulphonate and sodium N-Z-hydroxydodecyl-N-methyl-taurate.

Examples of suitable zwitterionic detergent-active compounds are: derivatives of aliphatic quaternary ammonium compounds, sulphonium compounds and phosphonium compounds in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilising group, such as 3-(N,N-dimethyl-N-hexadecyl-ammonium) propane-l-sulphonate betaine, 3-(N,N-dimcthyl-N-hexadecyl ammonium)-2-hydroxypropane-l-sulphonate betaine, 3-(dodecylmethyl-sulphoniurn )propane- 1-sulphonate betaine, and 3-(cetylmethylphosphonium)ethane sulphonate betaine.

Further examples of suitable detergent-active compounds commonly used in the art are given in Surface Active Agents, vol. I by Schwartz and Perry (lnterscience 1949) and Surface Active Agents, vol. II by Schwartz, Perry and Berch (Interscience 1958), the disclosures of which are included by reference herein.

The heterocyclic dicarboxylic acid salts of the invention may comprise the whole of the detergency builder content of a detergent composition of the invention. However, if desired, mixtures of one or more of these heterocyclic dicarboxylic acid salts with one or more known detergency builders may be used. As one of the objects of the invention is to provide an effective detergent composition containing either no phosphorus or at most only a low level of phosphorus, it is preferred that any such other detergency builders should not be phosphorus-containing compounds. Usually the total amount of detergency builders in a detergent composition of the invention will be from about 5 to about 70% by weight of the detergent composition. Many detergency builders are known, and those skilled in the art of formulating fabricwashing detergent compositions will be familiar with these materials. Examples of known detergency builders are sodium tripolyphosphate; sodium orthophosphate; sodium pyrophosphate; sodium trimetaphosphate; sodium ethanel-hydroxy-1,1-diphosphonate; sodium carbonate; sodium silicate; sodium citrate; sodium oxydiacetate; sodium nitrilotriacetate; sodium ethylene-diaminetetraacetate; sodium salts of long-chain dicarboxylic acids, for instance straight chain (C to C succinic acids and malonic acids; sodium salts of alpha-sulphonated long-chain monocarboxylic acids; sodium salts of polycarboxylic acids; i.e. acids derived from the polymerisation or copolymerisation of unsaturated carboxylic acids and unsaturated carboxy acid anhydrides such as maleic acid, acrylic acid, itaconic acid, methacrylic acid, crotonic acid and aconitic acid, and the anhydrides of these acids, and also from the copolymerisation of the above acids and anhydrides with minor amounts of other monomers, such as vinyl chloride, vinyl acetate, methyl methacrylate, methyl acrylate and styrene; and modified starches such as starches oxidised, for example using sodium hypochlorite, in which some anhydroglucose units have been opened to give dicarboxyl units.

In addition to the detergent-active compounds and detergency builders, a detergent composition of the invention may contain any of the conventional detergent composition ingredients in any of the amounts in which such conventional ingredients are usually employed therein. Examples of these additional ingredients are lather boosters, such as coconut monoethanolamide and palm kernel monoethanolamide; lather controllers; inorganic salts such as sodium sulphate and magnesium sulphate; chlorinereleasing bleaching agents such as trichloroisocyanuric acid and sodium and potassium dichloroisocyanurates; antiredeposition agents, such as sodium carboxymethylcellulose; and, usually present only in minor amounts, perfumes, oolourants, fluorescers, corrosion inhibitors, germicides and enzymes.

A detergent composition of the invention can be prepared using any of the conventional manufacturing techniques commonly used or proposed for the preparation of detergent compositions, such as slurry-making followed by spray-drying or spray-cooling, and subsequent dry-dosing of sensitive ingredients not suitable for incorporation prior to the drying step. Other conventional techniques, such as noodling, granulation, and mixing by fluidisation in a fluidised bed, may be utilised as and when necessary. Such techniques are familiar to those skilled in the art of detergent composition manufacture.

By using such conventional manufacturing techniques, a detergent composition of the invention may be prepared in any of the common physical forms associated with detergent compositions, such as powders, flakes, granules, noodles, cakes, bars and, in some cases, liquids.

The invention is illustrated by the following examples, in which all parts and percentages are given by weight.

EXAMPLE 1 Two detergent powders having the following formulations were prepared by conventional techniques.

Components: Parts, percent Sodium dodecyl benzene sulphonate 18 Detergency builder 1 50 Alkaline sodium silicate Sodium sulphate 12 Fluorescers, perfumes, antiredeposition agents,

water, etc. to 100 Exacilnple 1: The disodium salt of pyridine-2,6-dlcarboxy c an Comparative Example A: Sodium tripolyphosphate.

The detergencies of these two detergent powders were compared by using them to wash Dacron/cotton test cloths, soiled with an artificial soil, in a Terg-O-Tometer' (supplied by US. Testing Inc.). The test details were as follows:

Rinse cycle:

1 minute 37 C. 18 H water (CazMg ratio-2:1)

Each detergent powder was tested twice, and the detergencies were determined from cloth reflectance readings. The following results were obtained:

TABLE I Detergency (percent) First Second Powder test test Average Example 1 51. 9 56. 6 54. 3 Comparative Example A 47. 3 49. 6 48. 3

These results show that the detergent powder of Example 1 possessed a washing ability superior to that of a conventional detergent powder built with 50% of sodium tripolyphosphate.

EXAMPLE 2 Two detergent powders having the following formulations were prepared by conventional techniques.

Components: Parts, percent Sodium dodecyl benzene sulphonate 16 Detergency builder 1 50 Alkaline sodium silicate 8 Sodium sulphate, fluorescers, perfumes, antiredeposition agents, water, etc. to

Exanple 2: The dlsodium salt of pyrldtne-2,6-dicarboxy c ac Comparative Example B: Sodium tripolyphosphat e.

When subjected to the test described in Example 1, the detergent powder of Example 2 proved to be superior to the conventional detergent powder of Comparative Example B.

EXAMPLE 3 Two detergent powders were prepared by conventional techniques and having the following essential formulations:

Components: Parts, percent Sodium dodecyl benzene sulphonate 20 Anhydrous alkaline sodium silicate Na msio,

ratio 2: 1) 10 Detergency builder 50 Sodium sulphate, water to 100 Example 3: The monohydrate of 4-hydroxy-pyrldine-2,6- dlenrboxylic acid.

Comparative Example C: Sodium trlpolyphospbate.

EXPERIMENT 1 The detergency efficiency of each detergent powder was calculated using reflectance measurements. The results obtained are given in Table II below:

TABLE II Detergency efliclency at concentration of- Detergent powder 0.075% 0.1% 0.125%

Example3 19 3 37 Comparative Example 0 13 23 31 These results show that the detergent powder of Example 3 had a greater detergency efiiciency than the conventional detergent powder of Comparative Example C.

7 EXPERIMENT 2 The previous experiment was repeated using three higher concentrations. The following results were obtained.

TABLE III Detergency efiicieucy at concentration ot- Detergent powder 0. 16% 0. 2% 0. 25%

Example 3 33 39 321 Comparative Example C 30 33 35 The results in Table III confirm the superiority of the detergent powder of Example 3 over that of Comparative Example C.

EXPERIMENT 3 This was the same as Experiment 1, except that the test cloth used was a commercially-available cottonbased test cloth (EMPA 101) supplied by the Swiss Materials Testing and Experimental Institute, Unterstrasse 11, 9001 Saint Gallen, Switzerland.

The follownig results were obtained.

TABLE IV Detergency efficiency at concentration ot- Detergent powder 0.075% 0. 1% 0. 125% Example 8 35 43 42 Comparative Example 30 37 41 The results in Table IV also demonstrate the good detergency efiiciency of the detergent powder of the invention.

EXPERIMENT Experiment 2 was repeated at two product concentrations using EMPA 101 test cloths. The results given in Table V below also show the detergency building properties of the detergent powder of the invention.

EXPERIMENT Experiment 1 was repeated using a fixed product concentration (0.1%) but with varying degrees of water hardness. The following results were obtained.

TABLE VI Detergency etficiency at water hardness oi- Detergent powder 0 H 4.5 H 9 H 13.5 H 18 H Example 3 59 60 57 58 47 Comparative Example 0... 62 60 56 54 38 The detergency efiiciency figures for the 18 I-I water are higher than the comparable figures obtained during Experiment 1 because a ditferent batch of the test cloth was used.

EXAMPLE 4 The ability of pyridine-2,6-dicarboxylic acid to act as an inhibitor for the decomposition of peroxy-compounds is illustrated by the following experiment.

Six test solutions were made up as follows, using 30 H (Ca only) water containing 0.5 ppm. of cupric ions:

Solution These test soluitons corresponded to 0.5% solutions a detergent composition containing 25% by weight of sodium perborate and various levels (from 0 up to 50% by weight) of pyridine-2,6-dicarboxylic acid.

Each test solution was heated from 20 C. up to C. over a period of one hour, and then maintained at 95 C. for a further 10 minutes. Subsequently, the percentage of sodium perborate lost was determined volumetrically using a potassium iodide titration. The following results were obtained.

Equivalent percent level of pyridine-2,0 Percent dicarboxylic acid sodium in the detergent perborate These results indicate that the heterocyclic dicarboxylic acids of the invention can function as stabilisers for peroxy-compounds in detergent compositions.

What is claimed is:

1. A detergent composition comprising by weight:

(a) from about 1 to about 50% of a detergent-active compound selected from the group consisting of anionic, nonionic, amphoteric and zwitterionic detergent-active compounds; and

(b) from about 1 to about 60% of a sodium salt of a chemical compound having the general formula:

HOOC lCOOH N wherein R is a hydrogen atom or a hydroxyl group.

2. A detergent composition according to claim 1, wherein said sodium salt comprises from about 5 to about 60% by weight of said detergent composition.

3. A detergent composition according to claim 2 which additionally comprises from about 1 to about 30% by weight of a peroxy-compound selected from the group consisting of sodium perborate and sodium percarbonate.

4. A detergent composition comprising by weight:

(a) from about 5 to about 35% of a detergent-active compound selected from the group consisting of anionic, nonionic, amphoteric and zwitterionic detergent-active compounds; and,

(b) from about 15 to about 55% of the disodium salt of pyridine-2,6-dicarboxylic acids.

-10 5. A detergent composition comprising by weight: References Cited (a) from about 5 to about 35% of a detcrgent -act1vc Chemical Abstracts VOL 54 p. 2212c.

compound selected from the group consisting of anionic, nonionic, zwitterionic and amphoteric de- MAYER WEINBLA'IT, Primary Examiner tergent-active compounds; and,

(b) from about 15 to about 55% of 4-hydroxj-pyridinc- 2,6-dicarboxylic acid.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3,759,833 Dated September 18, 1973 InVentm-(S) Donald Bannerman James Easton; George Kerr Rennie and Christopher Charles Storer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Heading, line 6, should read: "Claims priority,

application Great Britain, January 5, 1971" Signed and sealed this 9th day of April 197E.

(SEAL) Attsst:

EDI/JARD I- LFLETCHERJR. C. I IARSHAL L DANE Attesting Officer Commissioner of Patents FORM POmSO (10459) USCOMM-DC 60376-P69 U,5. GOVERNMENT PRINTING OFFICE: "89 O-3G6-SJI, 

